TABLE 2.

Possible cases of laboratory cross-contamination detailing symptoms, therapy, and final diagnosis

Case	Reason investigateda	Anti-TB drugs	Assessment conclusion
M	CXR—upper zone shadowing, cavitation; clinically consistent	Full course	Presumed case of TB; no obvious epidemiological link to clustered cases possible laboratory contamination between two known cases
N	CXR—upper zone shadowing and effusion; pleuritic chest pain	Full course	Treated as case of TB; symptoms and signs persisted posttreatment
O	Fine-needle aspirate of persisting lymphadenopathy	Unknown	Unknown—case notes lost
P	CXR—upper zone shadowing; clinically consistent	Full course	Presumed case of TB; no obvious epidemiological link to clustered cases: possible laboratory contamination between two known cases
Q	CXR—effusion, pneumothorax; breathless, cachexia, persistent cough	Unknown	Known congestive cardiac failure and carcinoma of bronchus; diagnosis of TB uncertain; already transferred abroad for terminal care before culture result
R	Unknown	Unknown	Case notes unobtainable
S	HIV positive, low CD4 counts, febrile, cough	Full course	Multiple other samples isolated MAIC; probably not TB but possibility of dual infection, hence not denotified
T	CXR—pleural effusion; immunocompromised post-renal transplant; past history of TB	Full course	Current diagnosis uncertain; fully treated in view of past history and immunocompromise

^aCXR, chest X ray; HIV, human immunodeficiency virus; MAIC, Mycobacterium avium-M. intracellulare complex; TB, tuberculosis.